Philip Doyle’s troops have never beaten England, and despite enjoying periods of territorial dominance, they rarely looked like doing so here.
England crossed as early as the ninth minute through wing Fiona Pocock, but despite their dominance at the set-piece, the floodgates never opened.
Ireland’s scramble defence saved them on a number of occasions – full-back Niamh Briggs alone made two try-saving tackles in the corners – but their first-up tackling let them down, as they missed more than 20 in total.
Briggs scuffed a penalty chance on 29 minutes, before Alphonsi careered through on a scissors move until grounded near the posts by Tania Rosser, but England zipped the ball to the corner for Kathering Merchant to make it 12-0 at the break.
Ireland had chances of their own but were let down by unforced errors, and the game slipped out of their reach when Amy Turner barged over after a quick tap on 56 minutes.
England coach Gary Street then bizarrely made six substitutions at once, but it made little difference to the hosts’ continuity, and McLean tacked on a penalty before Alphonsi picked up a loose ball near the Irish line for a gift of a bonus-point try late on. Ireland have the USA – 51-0 victors over Kazakhstan – up next on Tuesday, needing to win to keep their semi-final hopes alive.
ENGLAND: D Waterman; K Merchant, E Scarratt, R Burford, F Pocock; K McLean, A Turner; R Clark, S Hemming, B Essex; J McGilchrist, H Fisher; M Alphonsi, C Spencer (capt).
Replacements: C Barras for Merchant, A Richardson for Burford, E Crocker for Hemming, C Purdy for Clark, T Taylor for McGilchrist, S Hunter for Fisher (all 62); LT Mason for Turner (72).
IRELAND: N Briggs (Clonmel/Munster); A Davis (Blackrock/Leinster), J O’Sullivan (Richmond/Exile), L Cantwell (UL Bohemians), N Stapleton (Old Belvedere/Leinster); H Brosnan (Highfield/Munster), T Rosser (Blackrock/Leinster); F Coghlan (capt, UL Bohemians/Munster), G Bourke (UL Bohemians/Munster), L Austin (UL Bohemians/Munster); K O’Loughlin (Clonmel/Munster), ML Reilly (Navan/Leinster); O Brennan (Blackrock/Leinster), C Molloy (Bristol/Connacht), J Neville (UL Bohemians/Munster).
Replacements: Y Nolan (Blackrock/Leinster) for Austin, S Houston (Blackrock/Leinster) for Cantwell (both 62) S Ryan (Blackrock/Leinster) for Neville (74).
Referee: S Corrigan (Australia).